1. Field of the Invention
The present invention relates to a printing device, a printing method, a computer program product, and a recording medium.
2. Description of the Related Art
In recent years, large offices are equipped with a plurality of printing devices such as printers that are connected via a network. At the same time, the problem of information leakage attributed to the printed material has been exposed. More specifically, because the printers are instructed to perform printing for a large number of employees, it is now a common occurrence that the confidential information, which is mentioned in the printed material outputted by a certain employee, is caught by another unintended employee.
With regard to that problem, printers are being configured to perform user authentication as a countermeasure against information leakage. In such user authentication, when receiving print data, a printer does not immediately perform printing but temporarily stores (spools) that print data in an embedded hard disk. The user who has sent the print data to the printer then goes to the installation site of the printer in order to perform a login operation and a printing instruction operation. Only after those operations by the user, the print data gets printed by the printer. In the following description, this form of usage is referred to as on-demand printing. Such on-demand printing is a superior printing technology by which it not only becomes possible to prevent information leakage, which is caused by the mix-up of printed material or caused by misplacing the printed material, but also becomes possible to reduce the amount of unnecessary printing or reduce the volume of unattended paper documents.
Herein, a known technique on password authentication can be cited as a leading specific example of user authentication without using an IC card (IC stands for integrated circuit). In order to perform password authentication at a printer, the user needs to input a user ID and a password from the touch-sensitive panel installed on the operation screen of the printer. However, inputting a large number of characters from the touch-sensitive panel is a cumbersome task. Hence, as a technique to reduce the efforts of a user while inputting the user ID, it is possible to display a plurality of user buttons on the touch-sensitive panel and allow each user to select a user button representing the own user. At that time, in order to enable selection of an intended user button from a plurality of user buttons, the user names can be sorted in the Japanese syllabary order or in the alphabetic order so that a user make selection using the initial letters. This way of management is similar to the known technique of address book management.
An example of an information system containing printers is disclosed in Japanese Patent Application Laid-open No. 2003-274064; while an example of on-demand printing is cited in product information/imagio Personal Authentication Kit|Ricoh Japan: [searched on Sep. 18, 2009], Internet <URL: http://www.ricoh.co.jp/imagio/mfp-sol/ic-card/function/function2.html>
In the on-demand technology specified in Non-patent literature 1, IC cards are used for user authentication. However, although such IC cards are superior in terms of allowing user authentication with a minimum key operation and in terms of being easy to use, the introduction of IC cards and card readers is an expensive investment. Besides, it becomes necessary that the user information on all users is registered in advance in the printers. For that, a dedicated system administrator needs to be employed. Hence, typically, the clients implementing the mechanism of user authentication using IC cards have been limited to relatively large-scale companies.
It is well known that on-demand printing is a superior technology for the present-day office environment. However, the mechanism of user authentication make it difficult for the smaller companies or business entities to introduce the on-demand printing technology. Thus, at present, there is required to implement the on-demand printing technology using a simple user authentication mechanism while eliminating the need to use IC cards and the need to employ a dedicated information system administrator.
Besides, in the technique of reducing the efforts of a user while inputting the user ID, it takes a large area on the touch-sensitive panel to display the tabs of all initial letters in the Japanese syllabary order as well as in the alphabetic order. In this case, it becomes necessary to switch between a screen displaying the Japanese syllabary order and a screen displaying the alphabetic order. This leads to increase the efforts for selecting a screen among these screens and make the input task more cumbersome. Moreover, in small companies or business entities, the number of users is commonly not so large that the user management needs to be done in the Japanese syllabary order as well as in the alphabetic order. Thus, the technique of user management using the Japanese syllabary order as well as the alphabetic order is unsuitable when on-demand printing is implemented with only a small number of users in mind.